Improvement in hot-blast ovens



2 Shegts-heeiz- 1. J. M. SMITH. Hot-Blast Oven.

No. 198,820. Patented Jan. 1,18%8.

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J. M. SMITH. Hot-Blast Oven.

N0.198,820. Patented Jan. I, 1878.

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.in the plane indicated by dotted line Fig. 1; and Fig. 3, Sheet 2, is a horizontal section taken through the oven in the plane damper, B, and a slide-valve,

Uut rnns'riirns PATENT OFFICE.

Jesse M. SMITH, or NEWARK, OHIO.

IMPROVEMENT m HOT-BLAST OVENS.

Specification forming part of Letters Patent No. 198,820, dated January 1,1878, application filed June 11, 1877.. I I r i To all whom it. may concern:

. Be it known that I, JEssE M. SMITH, of Newark, in the county of Licking and State of Ohio, have invented a new and useful 1mprovement in HotrBlast Ovens for Metallurgic and other Furnaces, of which the following is I a specification the nature of my invention consists in a novel construction .of oven, whereby the operation of heating is conducted with great facility and at a comparatively small cost, as will be understood from the following. description.

In the annexed drawings, Figure 1 is a diametrical section through the oven, taken in the plane indicated by dotted line x m on Fig. 2. Fig. 2 isa diametrical section taken a y in indicated by dotted line 2 z in Fig. 2.

Similar letters of reference indicate corresponding parts. I The oven is heated by gas, whichmay be obtained from the waste gases of the blastfurnace, or from the distillation of coal, wood,

and various kinds of oils.

The gas is conducted into the oven through the flue A, which is provided with a slide- G. Passing through shortflue D, the gasentersthecombustionchamber E, where it meets with the air necessary for the combustion. The air enters the combustion'chamber through an opening provided with a valve, M, and through the flues N and small openings 0. The said valve serves to regulate the amount of air entering in agiven time. A second supply of air is furnishedby an air-inlet, having a regulating-valve, P, and through openings 0,

which communicate with said air-inlet, and are located on a higher level than the flues N.

The flame and products of combustion pass from the combustion-chamber througha series of fines, F, formed by fire-brick arches F which are supported along their lengthwise v middle by division-walls F ,'and are arranged one above the other, with an opening at the end of each arch, to allow theflame to pass to the next flue above. Arriving, by this zigf zag course, at the top of the oven, the products of combustion pass'out through a chimney, G, avalve or cap, H, which is used to cover the chimney, being open.

' The gas is allowed to burn in the oven until the mass of brick-work is heated to a red heat. The gas-valve Qand also the chimney- I valve H, are then closed. Valve I is now opened, which allows the cold air which is to be heated to enter the oven at its upper end.

This air is conducted through the same pas- "the hot-blast main L, thence to the furnace.

In practice I shall use the ovens in groups of two or more,

heated by the burning gas. The ovens will be changed from air to gas as often as may be required to raise the proper temperature.

The oftener they are. changed the higher the temperature of the air will be.

The brick-work is inclosed in' a, wroughtiron shell, circular in form, and constructed with a hemispherical crown or dome.

In case the flues F become obstructed by dust they may cleaned through the doors R by means of steam or air jets or a scraper.

Having thus described my invention, I claim as new and desire to secure by Letters Pat- C 1. The hot-blast oven, circular in form, with dome-shaped top, in combination with horizontal walls, or arches and cross-walls, substantially as and for the purposes specified. 2. The oven constructed to form the chamber E, the flues N, and the holes 0, as shown and descnibed, for the purpose specified.

3. The combination of the air-inlet and its valve P, the openings Q, communicating with said air-inlet, the chamber E, and flue F, all

as shown and described.

a JESSE MERnIcK SMITH.

Witnesses: j

JAs. H. SMITH, LUTHER J J oHNsoN.

so that while air is being heated in one group the others are being 

